CLIFFHANGER: Sharon Lee, with her lawyer yesterday, was about to reveal Liu “donor” names when time ran out. Photo: Stefan Jeremiah

Day 5 at the John Liu campaign-finance trial ended in a cliffhanger yesterday after prosecutors called a key aide to the embattled city comptroller to the witness stand.

Former Liu spokeswoman Sharon Lee — who recently left the Comptroller’s Office to work on Liu’s mayoral campaign — was about to reveal whom she asked to contribute to his political war chest when time ran out for the day’s proceedings.

Earlier, Lee admitted in Manhattan federal court that she had offered to illegally reimburse unspecified donors who contributed to Liu’s campaign.

After excusing the jury, Judge Richard Sullivan warned Lee about the potential consequences of whatever she next told the jury.

“Any testimony you give could result in exposure to prosecution. Do you understand?” he asked.

“Yes,” Lee replied.

Lee was initially set to testify under a nonprosecution agreement with the feds, but she backed out on the eve of the trial of former Liu campaign treasurer Jia “Jenny” Hou and fund-raiser Xing Wu “Oliver” Pan.

Hou and Pan are charged with scheming to defraud the city Campaign Finance Board of matching funds by funneling illegal contributions into Liu’s campaign through the use of “straw donors,” some of whom got money from an undercover FBI agent as part of a sting operation.

Last week, prosecutor Justin Anderson said Lee’s immunity deal collapsed after she said she would testify that Liu’s campaign didn’t know about her efforts to provide funding through straw donors.

Anderson also said that her testimony — which is expected to come during Lee’s cross-examination — would amount to perjury.

Outside court, Lee’s lawyer, Andrew Lankler, said she would acknowledge she asked her mom, aunt and several friends to contribute to Liu’s campaign, and offered to reimburse them “as a a way of demonstrating how important the campaign was to her.”

“She made the offer on her own,” Lankler said. “If there was a scheme, she wasn’t part of it.”